New research on the dark matter density of dwarf galaxies has provided the first observational evidence of dark matter heating.
Dark matter heating is the effect of dark matter heating up and moving around as a result of star formation in galaxies. The team from the University of Surrey investigated dark matter density at the centres of nearby dwarf galaxies to make the first observation.
Scientists have found evidence that dark matter can be heated up and moved around, as a result of star formation in galaxies. The findings provide the first observational evidence for the effect known as ‘dark matter heating’.
Dark matter heating
When stars form, strong winds can push gas and dust away from the centre of the galaxy. The galaxy’s centre had less mass as a result of this, which affects how much gravity is felt by the dark matter.
With less gravitational attraction, the dark matter gains energy and moves away from the centre of the galaxy, an effect called dark matter heating.
Professor Justin Read, the lead author of the study and Head of the Department of Physics at the University of Surrey, said: “We found a truly remarkable relationship between the amount of dark matter at the centres of these tiny dwarfs, and the amount of star formation they have experienced over their lives. The dark matter at the centres of the star-forming dwarfs appears to have been ‘heated up’ and pushed out.”
But what is dark matter?
Professor Matthew Walker, a co-author from Carnegie Mellon University, added: “This study may be the “smoking gun” evidence that takes us a step closer to understanding what dark matter is. Our finding that it can be heated up and moved around helps to motivate searches for a dark matter particle.”
In the future, the team hopes that this work will be expanded by measuring central dark matter density in a larger sample of dwarf galaxies. They would like to push towards even fainter galaxies and test a wider range of dark matter models.